add test for asynchronously adding subtests
add test for asynchronously adding subtests

Joris-van-der-Wel/tape,wbinnssmith/tape,substack/tape,gritzko/tape,mstade/tape,beni55/tape,webthusiast/tape,feross/tape,feross/tape,IbpTeam/node-tape,jtlapp/tape,maslennikov/testimony,ljharb/tape,substack/tape,brycebaril/tape,wbinnssmith/tape,joakimbeng/tape,gritzko/tape,ajoslin/tape,jtlapp/tape,ljharb/tape,ljharb/tape,IbpTeam/node-tape,beni55/tape,webthusiast/tape,hafeez-syed/tape,feross/tape,MignonCornet/tape,hafeez-syed/tape,joakimbeng/tape,gritzko/tape,Joris-van-der-Wel/tape,brycebaril/tape,joakimbeng/tape,hayes/tape,mstade/tape,hayes/tape,wbinnssmith/tape,beni55/tape,brycebaril/tape,mstade/tape,ajoslin/tape,maslennikov/testimony,hayes/tape,maslennikov/testimony,MignonCornet/tape,ajoslin/tape,webthusiast/tape,substack/tape,jtlapp/tape,MignonCornet/tape,Joris-van-der-Wel/tape,IbpTeam/node-tape,hafeez-syed/tape